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BACKGROUND Dementia shortens life expectancy; estimates of median survival after the onset of dementia have ranged from 5 to 9.3 years. Previous studies of people with existing dementia, however, may have underestimated the deleterious effects of dementia on survival by failing to consider persons with rapidly progressive illness who died before they could(More)
When survival data are collected as part of a prevalent cohort study with follow-up, the recruited cases have already experienced their initiating event, say onset of a disease, and consequently the incidence process is only partially observed. Nevertheless, there are good reasons for interest in certain features of the underlying incidence process, for(More)
There is a well-recognized association between dysontogenetic tumors of the spinal cord (including teratomas and enterogenous cysts) and dysraphic congenital spinal malformations. The authors present a case of an adult with an intramedullary mature teratoma (IMMT) at the level of C1-2 of the cord associated with dysraphic congenital spinal malformations.(More)
—Optical label swapping of 10-Gb/s nonreturn-to-zero (NRZ) labels attached to 40-Gb/s return-to-zero payloads is demonstrated using payload envelope detection (PED) circuits based on 40-Gb/s clock recovery with nanosecond locking time. The circuits generate a digital envelope signal representing the payload location without having to process the 40-Gb/s(More)
The pattern of deterioration in patients with Alzheimer's disease is highly variable within a given population. With recent speculation that the apolipoprotein E allele may influence rate of decline and claims that certain drugs may slow the course of the disease, there is a compelling need for sound statistical methodology to address these questions.(More)
Papillary thyroid carcinoma with metastasis to the frontal skull is extremely rare. We report a case of unsuspected papillary thyroid carcinoma with frontal skull metastasis. The patient was a 62-year-old African American woman with presentation of a 4-cm firm, painless, immobile, ill-defined mass at the right forehead. Ultrasound and computer tonography(More)
In many medical experiments, data are collected across time, over a number of similar trials, or over a number of experimental units. As is the case of neuron spike train studies, these data may be in the form of counts of events per unit of time. These counts may be correlated within each trial. It is often of interest to know if the introduction of an(More)
Ecological and biological processes can change from one state to another once a threshold has been crossed in space or time. Threshold responses to incremental changes in underlying variables can characterize diverse processes from climate change to the desertification of arid lands from overgrazing. Simultaneously estimating the location of thresholds and(More)
It is a widely held belief that multiple sclerosis is a disease with a long latent period that is preceded by heightened susceptibility before adolescence. There has, however, been little research focused on either the estimation of the latent period or determination of the susceptibility period. In this article, we present a critical assessment of the(More)